Re: Problems with solving integrals in Mathematica 9
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- Subject: [mg131010] Re: Problems with solving integrals in Mathematica 9
- From: Richard Fateman <fateman at cs.berkeley.edu>
- Date: Mon, 3 Jun 2013 03:35:42 -0400 (EDT)
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On 6/1/2013 3:06 AM, Jost Adler wrote:
> Has anybody encountered the same problems with solving integrals in Ver. 9 as I did?
>
> Here a very simple example:
>
> Integrate[D[f[x], x] / f[x], {x, 0, T}]
>
...
In case the previous explanations are too obscure, may I point out that
it is the [second?] fundamental theorem of the integral calculus (FTIC)
which allows one to compute the
integral of f'(x) with respect to x, from A to B
by computing f(B)-f(A).
FTIC requires some constraints on f. Read your favorite calculus text
to learn more. (Depending on the sophistication of your text, you may
see various formulations of these constraints.)
So Mathematica is doing the right thing in version 9 in this situation,
I think.